All of your questions and concerns can be answered by anyone who has paid attention to the industry the last 20 years. Before PhysX how many APIs had cross vendor GPGPU support for physics or otherwise, how about now? I've been waiting 21 years since the first time I read about dedicated hardware support for ray tracing. The only way CAD software, API implementations and competing vendors are going to bring it to market is if one puts it out a few years early. This time it's technically not 100% proprietary and AMD will be bringing a competing solution under an existing API. Nvidia has taken the necessary first step and AMD fans don't have a reason to complain about it.
Ray tracing is a minor feature to what RTX GeForce and RTX Quadro brings. But everyone both happy and mad latch onto pretty much that one thing because of advertising. 0 of those 5 games actually use ray tracing to render the game. It's just minor effects. Turn it off and be happy that one day this moment will have brought whats coming. Despite accounting for up to 50% of their profit, gaming gpu's are a by product of their professional products. Producing common core designs keeps the profit margins in the professional space higher.
People who aren't even remotely in the market for an upgrade are whining like crazy for what reason? I know there are some compulsive upgraders out there. I personally dont like to spend more than $350 and I do ray tracing on CPU quite often. It pretty much narrowed me down to the RTX 2060. AN RX 590 is a tempting savings but no. Vega 64 can probably be gotten on sale. 1070 doesn't make any sense. 1080 generally not "refurbished/used" isn't in that price range. I will be excited when a renderer I use can do even 1 FPS on my card.
Final note, the PhysX engine is available on PS4 and XBox One and yeah thats AMD hardware lol. Can't tell you anyones using it.